Great Loop Lock Reference

Thomas J. O'Brien Lock

Reviewed planning reference for lock approach, communications, and float-plan preparation.

Chicago / Illinois Waterway

Thomas J. O'Brien Lock

Chicago, IL

Latitude / Longitude41.651617
-87.567083

Phone773-646-2183

VHF Channel16/14

Operating AuthorityNot listed

Last ReviewedNot listed

Lock Location

Zoomed-in location for this Great Loop lock reference.

About This Lock

Segment: Chicago / Illinois Waterway. Route status: core inland-river route from Great Lakes to Mississippi. Waterway Guide lists phone; USACE water-safety guidance says VHF 14 for Illinois Waterway locks and Ch.16 for calling/distress. Source: https://www.mvr.usace.army.mil/Missions/Navigation/Lock-and-Dam-Phone-Numbers/

Before You Arrive

Fenders ready
Lines ready
Crew briefed
PFDs on deck
Radio on correct channel
Call / monitor lock
Check current notices

Plan With FPW

Add lock planning context to your route and account for lock delays in your float plan.

Plan a Float Plan

Official Source

Official source

Open official source

Navigation Safety Note

This page is a planning reference, not a substitute for official notices, charts, lockmaster instructions, or current local conditions. Always confirm lock status, operating hours, closures, restrictions, and instructions with the official authority before arrival.